General Tracking Information

Overall, 96.9% of samples had a recorded gaze position.

The total number of blocks in this design was 105. This was calculated as the number of trials multiplied by the number of blocks within each trial.

Out of those blocks, 0 were completely missing data. These missing blocks can be seen below:

trials_this_n block n tracked perc

The percent of samples tracked within each block can be seen below:

trials_this_n block n tracked perc
0 fixation 980 980 100.00
0 stimulus 3499 3370 96.31
0 text 2989 2806 93.88
1 fixation 977 977 100.00
1 stimulus 3501 3501 100.00
1 text 3009 2893 96.14
2 fixation 993 993 100.00
2 stimulus 3497 3497 100.00
2 text 3006 2751 91.52
3 fixation 978 978 100.00
3 stimulus 3500 3500 100.00
3 text 3009 3009 100.00
4 fixation 992 883 89.01
4 stimulus 3499 3321 94.91
4 text 3004 3004 100.00
5 fixation 979 858 87.64
5 stimulus 3501 3201 91.43
5 text 3008 3008 100.00
6 fixation 992 992 100.00
6 stimulus 3500 3365 96.14
6 text 3009 3009 100.00
7 fixation 992 992 100.00
7 stimulus 3498 3217 91.97
7 text 3003 2883 96.00
8 fixation 980 819 83.57
8 stimulus 3501 3501 100.00
8 text 3003 3003 100.00
9 fixation 981 981 100.00
9 stimulus 3498 3347 95.68
9 text 3010 2897 96.25
10 fixation 992 992 100.00
10 stimulus 3498 3231 92.37
10 text 3009 2910 96.71
11 fixation 993 993 100.00
11 stimulus 3499 3382 96.66
11 text 3004 2857 95.11
12 fixation 979 979 100.00
12 stimulus 3500 3355 95.86
12 text 3003 2679 89.21
13 fixation 980 980 100.00
13 stimulus 3499 3499 100.00
13 text 3009 2919 97.01
14 fixation 994 981 98.69
14 stimulus 3498 3498 100.00
14 text 3009 2841 94.42
15 fixation 993 993 100.00
15 stimulus 3498 3347 95.68
15 text 3009 2793 92.82
16 fixation 992 992 100.00
16 stimulus 3499 3499 100.00
16 text 3010 2722 90.43
17 fixation 990 990 100.00
17 stimulus 3500 3383 96.66
17 text 3008 2862 95.15
18 fixation 975 975 100.00
18 stimulus 3500 3370 96.29
18 text 3009 3009 100.00
19 fixation 992 992 100.00
19 stimulus 3500 3500 100.00
19 text 3003 3003 100.00
20 fixation 979 979 100.00
20 stimulus 3500 2857 81.63
20 text 3008 2824 93.88
21 fixation 976 976 100.00
21 stimulus 3498 3312 94.68
21 text 3010 3010 100.00
22 fixation 992 992 100.00
22 stimulus 3500 3500 100.00
22 text 3008 2849 94.71
23 fixation 974 974 100.00
23 stimulus 3500 3373 96.37
23 text 3004 3004 100.00
24 fixation 980 980 100.00
24 stimulus 3499 3499 100.00
24 text 3009 2916 96.91
25 fixation 992 992 100.00
25 stimulus 3499 3499 100.00
25 text 3008 2871 95.45
26 fixation 976 976 100.00
26 stimulus 3500 3377 96.49
26 text 3008 2859 95.05
27 fixation 975 975 100.00
27 stimulus 3516 3516 100.00
27 text 3005 2744 91.31
28 fixation 979 806 82.33
28 stimulus 3500 3339 95.40
28 text 3009 2888 95.98
29 fixation 974 974 100.00
29 stimulus 3500 3500 100.00
29 text 3003 3003 100.00
30 fixation 981 778 79.31
30 stimulus 3499 3499 100.00
30 text 3009 2885 95.88
31 fixation 976 976 100.00
31 stimulus 3500 3500 100.00
31 text 3007 2897 96.34
32 fixation 975 975 100.00
32 stimulus 3499 3339 95.43
32 text 3004 3004 100.00
33 fixation 980 980 100.00
33 stimulus 3501 3362 96.03
33 text 3009 3009 100.00
34 fixation 991 991 100.00
34 stimulus 3498 3388 96.86
34 text 3008 3008 100.00

Gaze Position

All gaze position data is taken after the instructions were completed. Presented data is average gaze position as given by the eyetracker. Samples where no eyetracking data is recorded are removed from the overall count.

  • % of time participant was gazing on screen: 99.89%.
  • % of time participant was gazing within the stimulus area during stimulus blocks: 99.53%.

Pupil Size

Distribution of Pupil Sizes

Eyelink reports pupil data from left and right eyes as well as the average of the two. The preprocessing pipeline performs mean and median normalization on all 3 measures relative to prefixation and fixation baselines. The following plots show the distribution of pupil sizes for samples where the participant has their gaze on the screen during the experiment (i.e. past the instructions block).

Pupil Sizes During Stimuli

Epoch Median

Median average (combined left and right values) pupil size is plotted for each stimulus block as a function of epoch. Raw values are plotted followed by prefixation and fixation-normalized values, respectively. Within stimulus blocks, patterns of change in pupil size are not different across the raw and two types of normalization, however the differences pupil size between blocks does differ across normalizations. The extent to which they differ is dependent on the variance in pupil size during the chosen normalization block across samples.

Pupil Size and Gaze Position

Median average pupil size are plotted as functions of gaze position during stimulus blocks. Only positions within the boundary of the stimulus area are plotted. Non-normalized median values are plotted first followed by prefixation normalized, and then fixation normalized.

Raw Pupil Size

Prefixation Normalized

Fixation Normalized